What is the kind of ID that short url use?

Question

What is the kind that they use in their short urls?

The kind where instead of being just numbers, they increment in things like: 7Hna7z

and that. I'm just starting to get into programming and I was thinking on doing that for a project. I just need a name or something to google it, or if anybody has a PHP or MySQL tutorial onto how to do it I would appreciate it greatly.

Thanks.

Answer 1

It's just an alphanumeric key that has been generated. It's guaranteed to be unique. In PHP, this can be a uniqID. You can see the documentation for more info: http://php.net/manual/en/function.uniqid.php